Cigarette making machines

ABSTRACT

Excess shreded tobacco is discarded from a filler stream moving on a conveyor in a cigarette making machine by trimming the excess and discarding the same therefrom. A pair of rotating disc knives having a rotating brush adjacent thereto removes the excess and the brush discards the same toward and against a plate that is rigidly mounted at one end thereof. The remainder of the plate flexes or bends in proportion with the mass flow rate or quantity of discard tobacco striking the same. The magnitude of the flexure is measured by strain gauges and is used as an indicator of the mass flow rate of the discard tobacco. A rigid plate having a pivotable mounting at one end and a spoon shape at the other may also be used, in which case, the indicator of the mass flow rate may include a screw conveyor adapted to pass discard tobacco against the spoon portion, a spring may be applied to limit displacement of the plate about the pivotable mounting and the plate is then used as one of two capacitive plates through which an electric circuit is passed, thereby providing a quantitiative indication thereof. Alternately, a restoring force may be applied to the plate by means of a fluid operated piston, the force necessary to prevent movement of the plate then provides the desired indicator.

1451 Nov. 6, 1973 CIGARETTE MAKING MACHINES [75] Inventors: FrancisAuguste Maurice Labbe,

Neuilly-sur-Seine, France; Edward George Preston; Clifford RussellMarritt, both of London, England [73] Assignee: Molins Limited, London,England [22] Filed: July 21, 1971 [21] Appl. No.: 164,505

[30] Foreign Application Priority Data July 23, l970 Great Britain35,746/670 [52] us. Cl. 131/211), 131/84 C [51] lnt.Cl. ..A24c 05/34[58] Field of Search 131/21, 21 D, 84,

' l3l/84C [56] References Cited UNITED STATES PATENTS 3,338,247 8/1967 1Labbe .4 131 21 1) FOREIGN PATENTS OR APPLICATIONS 331,333 7 1930 GreatBritain 131 84 c Primary Examiner-Joseph S. Reich Att0rney-Craig,Antonelli & Hill [57] g ABSTRACT Excess shreded tobacco is discardedfrom a filler stream moving on a conveyor in a cigarette making machineby trimming the excess and discarding the same therefrom. A pair ofrotating disc knives'having a rotating brush adjacent thereto removesthe excess and the brush discards the same toward and against a platethat is rigidly mounted at one end thereof. The remainder of the plateflexes or bends in proportion with the mass flowv rate or quantity ofdiscard tobacco striking the same. The magnitude of the flexure ismeasured by strain gauges and is used as an indicator of the mass flowrate of the discard tobacco. A rigid plate having a pivotable mountingat one end and a spoon shape at the other may also be used, in whichcase, the indicator of the mass flow rate may include a screw conveyoradapted to pass discard tobacco against the spoon portion, a spring maybe applied to limit displacement of the plate about the pivotablemounting and the plate is then used as one of two capacitive platesthrough which an electric circuit is passed, thereby providing aquantitiative indication thereof. Alternately, a restoring force may beapplied tothe plate by means of. a fluid operated piston, the forcenecessary to prevent movement of the plate then provides the desiredindicator.

12 Claims, 6 Drawing Figures CIGARETTE MAKING MACHINES This invention isconcerned with cigarette making machines in which a trimmer removes partof the cigarette filler stream before the stream is enclosed in awrapper to form a cigarette rod. The part of the stream removed by thetrimmer may be termed the discard tobacco.

According to this invention a trimming unit for trimming the cigarettefiller stream in a cigarette making machine includes means for throwingdiscard tobacco on to a plate, and means for monitoring the force whichthe tobacco applies to the plate, as an indication of the mass flow rateof the discard tobacco. A preferred arrangement is one in which theplate is resiliently movable and'in which the monitoring system issensitive to the amount of movement of the plate.

In an alternative arrangement the plate is movable but is held in asubstantially fixed position by a restoring force which variesautomatically to balance the force of the tobacco on the plate, themonitoring system being sensitive tothe magnitude of the restoringforce.

The movement of the plate may be converted into a signal to provide avisible indication of the mass flow rate of the discard tobacco.Alternatively, or in addition, a signal responsive to the movement ofthe plate may be used to control'the initial feed rate of the tobaccoused to form the stream, so as to maintain the mass flow rate of the Idiscard tobacco substantially constant, for example as described in U.S.Pat. No. 3,338,247.

The plate is preferably arranged to deflect the stream ofdiscard'tobacco towards a receiver, but as an alternative the inertia ofthe discard tobacco stream could be entirely lost in the impact with theplate.

In a preferred arrangement the trimmer comprises means, for example twocooperating discs, for separating the discard tobacco from the main bodyof the tobacco stream, and a rotary brush for brushing away the discardtobacco; the trimmer may for example be as described in U.S. Pat. No.3,338,247. The brush in this case preferably throws the discard tobaccoagainst the resiliently mounted plate.

An example of apparatus according to this invention is shown in theaccompanying drawings. In these draw mgs:

FIG. 1 is a plan view of a double-disc trimmer with a rotary brush and aresiliently mounted deflector plate;

F IG. 2 is a side viewshowing the path of the deflected discard tobaccotowards a feed screw;

FIG. 3 is a view of the deflector plate in a direction normal totheplane of the plate;

FIG. 4 is a block diagram illustrating the use of the inventionin acigarette making machine;

FIG. 5 shows diagrammatically a different sensor plate; and

FIG. 6 shows diagrammatically another sensor plate in accordance withthe present invention.

The trimmer shown in the drawings includes two discs 2 and 4 whichrotate in opposite directions so that the adjacent parts of theirperipheries move in the direction of the tobacco stream (that is to say,the cigarette filler stream) which approaches the trimmer in thedirection of the arrows 6. The tobacco stream (not shown) is carriedfrom above by an air-pervious band with the aid of suction. The banddoes not move quite horizontally but moves in a slightly downwarddirection parallel to the plane of the discs as shown in FIG. 2. Themain body of the tobacco stream continues past the trimmer discs, butpart of the stream is separated from the remainder by the discs, whichcan move up and down to vary the amount of discard tobacco.

Below the discs there is a rotary brush 8 consistingof a number ofcircumferentially spaced radial ribs 10 joined to an integral side wall.The brush is driven by a shaft 12 which moves up and down with thediscs. As shown in FIG. 1, the shaft 12 is inclined to the line joiningthe centres of the discs, so that the brush throws the discard tobaccoobliquely away from the remaining stream of tobacco along the directionof arrows 14. The stream of discard tobacco moving in the direction 14hits'a deflector plate 16 which deflects the stream downwards inapproximately the direction of the arrows 18. The discard tobacco-thusenters a trough 20 containing a feed screw 22 which carries away thediscard tobacco; at the downstream end of the feed screw there may forexample be another conveyor which feeds the discard tobacco back intothe hopper of the cigarette making machine.

As shown best in FIG. 3, the deflector plate 16 is T- shaped andconsists of a deflector portion 18, against which the discard tobaccoimpinges, and a narrower flexible portion 20. The deflector plate ismounted on a casing wall 23 by screws 24 passing through holes 26 in theend of the flexible portion 20. Thus the deflector plate is clamped tothe casing but can move owing to the flexibility of the portion 20.

' The clamped end of the plate could alternatively lie outside thecasing wall 23, and the portion 20 of the plate could pass through aslot in the casing wall.

Between the clamped end and the deflector portion 18, strain gauges 28are bonded to both sides of the flexible portion 20 of the plate.Electrical leads 30 from the strain gauges are connected to any suitableelectrical circuit by which the amount of movement of the plate can bedetected as a result of the changing resistance of the strain gauges dueto varying degrees of flexing of the portion 20-of the plate.

In one preferred arrangement shown diagrammatically in FIG. 4 the signalprovided an electrical circuit 32 in response to the movement of thedeflector plate is fed via an amplifier 34 into an integrator circuit 36from which an average signal (i.e. representing the average over apredetermined interval of time) is transmitted to a device 38 forvarying the speed of the cigarette machine hopper 40 in order tomaintain the mass flow rate of the discard tobacco at a substantiallyconstant level. For example, the proportion of tobacco removed from thetobacco stream by the trimmer may be set approximately at a value ofbetween 20 percent and 25 percent by weight of the initial tobaccostream formed from the tobacco delivered by the hopper.

Instead of being flat as shown in the drawings, the deflector portion ofthe plate may be concave, for example spoon-shaped, as shown by thedeflector portion 18' in FIG. 5, to help in concentrating the stream ofdiscard tobacco deflected by the plate; that is to say, to prevent thestream from spreading excessively upon impact with the plate.

Instead of -the deflector portion of the plate being movable by virtueof flexing of part of the plate, the plate may be more rigid, as shownin FIG. 5, and may be pivotally mounted at 42 on the casing, with aspring 44 to restrain pivotal movement. In this case pivotal movement ofthe plate against the action of the spring may for example be monitoredby any sort of displacement transducer; for example, the plate maycooperate with a fixed plate 46 to form a capacitor so that thecapacitance between the two plates varies according to the position ofthe deflector plate.

Instead of the resiliently movable deflector plate being mounted in thepath of the discard tobacco stream thrown from the trimmer by therotarybrush, the deflector plate may for example be mounted at thedischarge end of the feed screw 22, as shown in FIG. 5. In this case thefeed screw would throw the tobacco against the plate, and the movementof the plate would again give an indication of the mass flow rate of thediscard tobacco.

FIG. 6 shows part of a pivotally mounted deflector plate 18 similar tothe deflector plate 18' in FIG. 5. However, instead of the displacementtransducer of FIG. 5, there is a fluid-powered device 48 which isconnected to the plate 18" and applies a restoring force which variesautomatically so as to balance the force applied to the plate by thetobacco and thus hold the plate in a substantially fixed position. Themagnitude of the restoring force is an indication of the mass flow rateof the tobacco.

We claim:

1. A trimming unit for trimming discard tobacco from a cigarette fillerstream in a cigarette making machine, including a plate, means forthrowing said discard tobacco on to said plate, and means for monitoringthe force which the discard tobacco applies to the plate as anindication of the mass flow of the discard tobacco.

2. A trimming unit according to claim 1 including means for mountingsaid plate in position to receive said tobacco and in which at least thepart of the plate engaged by the tobacco is resiliently movable, saidanother part of the plate which is rigidly mounted at one end.

4.. A trimming unit according to claim 3 including strain gages securedto the flexible part of the plate for monitoring the movement thereof.

5. A trimming unit according to claim 1 including movable mounting meansat one end of the plate automatic means for applying a restoring forceadapted to monitoring means being sensitive to the amount of movement ofthe plate.

3. A trimming unit according to claim 2 including means for rigidlymounting said plate at one end thereof and in which the part of theplate which is struck by the tobacco can move as a result of flexing ofbalance the force of the tobacco on the plate, the monitoring meansbeing sensitive to the magnitude of the restoring force.

6. A trimming unit according to claim 5 in which the automatic meansincludes a fluid-powered device.

7. A trimming unit according to claim 1 in which the plate is arrangedto deflect the discard tobacco towards a receiver.

8. A trimming unit according to claim 7 in which the part of the platewhich is struck by the tobacco is concave so as to reduce the tendencyof the discard tobacco stream to spread after impact with the plate.

9. A trimming unit according to claim 1 including a rotary brusharranged to throw the discard tobacco towards the plate.

10. A trimming unit according to claim 9 including two cooperatingrotating discs which separate the discard tobacco from the filler streamand wherein the brush removes the separated tobacco therefrom.

11. A cigarette making machine according to claim 1 including adjustablemeans for forming said filler stream, means to convey said streamthrough said trimming unit and means responsive to said monitoring meansfor controlling said adjustable means so as to maintain the mass flowrate of discard tobacco substantially constant.

12. A trimming unit for trimming the cigarette filler stream in acigarette making machine, including means for throwing discard tobaccoon to a deflector plate, said plate comprising a wide part which isstruck by the discard tobacco, and a narrow, flexible part which ismounted at one end on a fixed structure, and including strain gaugeswhich are secured to the narrow part of the plate and provide an outputsignal indicative of the amount by. which the narrow part of the plateis flexed by the force of the tobacco.

1. A trimming unit for trimming discard tobacco from a cigarette fillerstream in a cigarette making machine, including a plate, means forthrowing said discard tobacco on to said plate, and means for monitoringthe force which the discard tobacco applies to the plate as anindication of the mass flow of the discard tobacco.
 2. A trimming unitaccording to claim 1 including means for mounting said plate in positionto receive said tobacco and in which at least the part of the plateengaged by the tobacco is resiliently movable, said monitoring meansbeing sensitive to the amount of movement of the plate.
 3. A trimmingunit according to claim 2 including means for rigidly mounting saidplate at one end thereof and in which the part of the plate which isstruck by the tobacco can move as a result of flexing of another part ofthe plate which is rigidly mounted at one end.
 4. A trimming unitaccording to claim 3 including strain gages secured to the flexible partof the plate for monitoring the movement thereof.
 5. A trimming unitaccording to claim 1 including movable mounting means at one end of theplate automatic means for applying a restoring force adapted to balancethe force of the tobacco on the plate, the monitoring means beingsensitive to the magnitude of the restoring force.
 6. A trimming unitaccording to claim 5 in which the automatic means includes afluid-powered device.
 7. A trimming unit according to claim 1 in whichthe plate is arranged to deflect the discard tobacco towards a receiver.8. A trimming unit according to claim 7 in which the part of the platewhich is struck by the tobacco is concave so as to reduce the tendencyof the discard tobacco stream to spread after impact with the plate. 9.A trimming unit according to claim 1 including a rotary brush arrangedto throw the discard tobacco towards the plate.
 10. A trimming unitaccording to claim 9 including two cooperating rotating discs whichseparate the discard tobacco from the filler stream and wherein thebrush removes the separated tobacco tHerefrom.
 11. A cigarette makingmachine according to claim 1 including adjustable means for forming saidfiller stream, means to convey said stream through said trimming unitand means responsive to said monitoring means for controlling saidadjustable means so as to maintain the mass flow rate of discard tobaccosubstantially constant.
 12. A trimming unit for trimming the cigarettefiller stream in a cigarette making machine, including means forthrowing discard tobacco on to a deflector plate, said plate comprisinga wide part which is struck by the discard tobacco, and a narrow,flexible part which is mounted at one end on a fixed structure, andincluding strain gauges which are secured to the narrow part of theplate and provide an output signal indicative of the amount by which thenarrow part of the plate is flexed by the force of the tobacco.